Method of transferring a material from first apparatus to second apparatus in the clean room and an assembly line

ABSTRACT

A transport enclosure arranged between a first apparatus and a second apparatus, all located in a clean room, is shielded from the clean room and maintained a degree of cleanliness which is cleaner than that of the clean room. Accordingly, the volume of space within the clean room requiring the highest degree of cleanliness is minimized, thereby reducing overall costs.

FIELD OF THE INVENTION

[0001] The present invention relates to an assembly line in a cleanroom, and particularly, the present invention relates to an assemblyline located in the clean room of a semiconductor assembly plant, inwhich a high degree of cleanliness is required.

BACKGROUND OF THE INVENTION

[0002] Referring to FIG. 5, a semiconductor assembly line formanufacturing semiconductor devices is installed in a clean room 100.The assembly line includes many facilities such as a variety ofmanufacturing apparatuses 100 and measuring apparatuses 111 used tomanufacture the semiconductor devices. The clean room is mainly made upof a first area 101 in which the apparatuses are located, and a secondarea in which control units 120 for controlling the apparatuses arelocated and where workers 130 manage the control units 120. In the firstarea 101, generally, an automatic transport system, for example atransport robot, is used.

[0003] The clean room 100 requires a special high degree of cleanliness,particularly in the first area 101. Workers that enter the clean roommust first take an air shower while wearing dust free garments, dustfree gloves, a dust free mask and clean shoes. If dust is somehowintroduced into the clean room, the semiconductor devices manufacturedin the clean room may be fatally.

[0004] It takes enormous cost and labor to manufacture a clean room andto maintain the cleanliness of the clean. Particularly manufacturing andmaintaining the first area 101 of the clean room is very expensive.Also, the larger the clean room, the more burdensome is the costs andlabor.

SUMMARY OF THE INVENTION

[0005] The object of the invention is to provide a relativelyinexpensive assembly system located in a clean room having a high degreeof cleanliness.

[0006] To achieve the object, in the typical invention of the presentapplication, a transporting enclosure arranged between first apparatusand second apparatus, all located in a clean room, is shielded from theclean room and maintained a second clean level cleaner than that of theclean room.

[0007] According to the present invention, the cleanest area, such asthe first area, is minimized in the clean room. As the cleanest areawhich is the most expensive to manufacture, is minimized, it can berealized to manufacture the clean room more inexpensively than theconventional clean room.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] While the specification concludes with claims particularlypointing out and distinctly claiming the subject matter which isregarded as the invention, it is believed that the invention, theobjects and features of the invention and further objects, features andadvantages thereof will be better understood from the followingdescription taken in connection with the accompanying drawings in which:

[0009]FIG. 1 is a plane view of a clean room according to a preferredembodiment of the present invention.

[0010]FIG. 2 is a plane view of a transport enclosure according to thepreferred embodiment.

[0011]FIG. 3 is a cross section of the transporting enclosure accordingto the preferred embodiment.

[0012]FIG. 4 is a cross section of another transport enclosure accordingto the preferred embodiment.

[0013]FIG. 5 is a plane view of a conventional clean room.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The present invention will be described hereinafter withreference to the accompanying drawings. The drawings used for thisdescription typically illustrate major characteristic parts in orderthat the present invention will be easily understood. In thisdescription, one embodiment is shown in which the present invention isapplied to a semiconductor assembly line located in a clean room.

[0015]FIG. 1 is a plane view of a clean room according to a preferredembodiment of the present invention.

[0016] In FIG. 1, a semiconductor assembly system is located in theclean room 1. The clean room is shielded from an external atmosphere andis maintained a first degree of cleanliness. Herein, a particular degreeof cleanliness is defined by a number of contaminants (such as dust) perunit volume.

[0017] A passing station 2, a first apparatus 3 and a second apparatus 4are located in the clean room 1. A transport enclosure 5 is arrangedbetween the passing station 2 and the first apparatus 3, and between thefirst apparatus 3 and the second apparatus 4.

[0018] The passing station 2 passes a semiconductor material 6 to thefirst apparatus 3 via a transport enclosure 5-1. In this embodiment, thesemiconductor material 6 is a semiconductor wafer.

[0019] The first apparatus 3 and the second apparatus 4 each carry outany one of various semiconductor manufacturing processes, such as anetching process, deposition process, lithography process, ionimplantation process, and so on.

[0020] The first apparatus 3 includes a first stage 3-1, a first chamber3-2 and a second stage 3-3. The first stage 3-1 receives thesemiconductor wafer 6 from the passing station 2 and introduces thesemiconductor wafer 6 into the first chamber 3-2. The first chamber 3-2receives the wafer 6 and treats the surface of the wafer with a firsttreatment. Then, the second stage 3-3 receives the treated wafer fromthe first chamber 3-2 and passes the treated wafer to the transportenclosure 5-2.

[0021] The transport enclosure 5-2 is arranged between the firstapparatus 3 and the second apparatus 4. The transporting enclosure 5-2transports the treated wafer 6′ from the first apparatus 3 to the secondapparatus 4. The transport enclosure 5 is shielded from the clean room 1and is maintained at a second degree of cleanliness. Preferably, thesecond degree of cleanliness is at least two to five times higher (lesscontaminants per unit volume) than the first degree of cleanliness. Inthis embodiment, the transport enclosure is comprised of a tube and atransportation system which is conveyed the tube together with thesemiconductor wafer. The transport system may be implemented by anywell-known transport robot or belt conveyor or robot arm.

[0022] The second apparatus 4 includes a first stage 4-1, a secondchamber 4-2 and a second stage 4-3. The first stage 4-1 receives thetreated wafer 6′ from the transport enclosure 5-2 and introduces thetreated wafer 6′ into the second chamber 4-2. The second chamber 4-2receives the treated wafer 6′ and treats the surface of the treatedwafer 6′ with a second treatment. Then, the second stage 4-3 receivesthe treated wafer from the second chamber 4-2 and passes the treatedwafer 6″ to the transport enclosure 5-3. The transport enclosure 5-3then transfers the treated wafer 6″ to an other apparatus (not shown).

[0023] A worker 8 putting on dust free garment works in the clean room1. A control unit 7 is located in the clean room. The control unit 7controls the first and second apparatus and the transport enclosure.

[0024] The insides of the passing station 2, the first apparatus 3-2,the second apparatus 4-2 and transport enclosure 5 are shielded from theclean room 1 and are maintained at a second degree of cleanliness levelwhich is greater than that of the clean room 1. That is, the seconddegree of cleanliness is at a higher quality which is sufficient formanufacturing semiconductor devices.

[0025] As described previously with reference to FIG. 5, in aconventional assembly facility, the entire first area 101 of the cleanroom 100 is maintained at the highest degree of cleanliness, since thefirst area contains the wafer as it is being processed by the variousapparatuses also contained in the first area 101.

[0026] In contrast, according to the present invention, the spacemaintained at the highest degree of cleanliness is limited to theprocessing apparatuses and the transport enclosures extendingtherebetween. As such, the overall volume of space which must bemaintained at the highest degree of cleanliness is substantially lessthan that of the conventional system. Accordingly, overall costs arereduced as well.

[0027] In one embodiment, the transport enclosure 5 is comprised of aplurality of tubes which may be combined with each other. Each tube iscomposed of translucent material or semitransparent material to allowfor visual inspection inside the tube. For example, a translucent resinand a semitransparent glass are known translucent materials. Thetransport enclosure has a large enough cross section to allow fortransfer of the semiconductor wafer therein. However, the space occupiedby the transport enclosure is preferably smaller than that of the firstor second apparatuses.

[0028] In FIG. 2, a example of a network of tubes of the transportenclosure is shown. The tube 5A is combined with a plurality of tubepieces 5A1, 5A2, 5A3. Each tube piece has a different length andconfiguration. The tube 5A is comprised of the straight tube piece 5A1,the crossing tube piece 5A2 and the curve tube piece 5A3. Thus, thecomposition of the plurality of tube pieces makes it possible toflexibly configure an assemble line. Further, it is relatively easy tochange the assembly line to other configurations as the need arises.

[0029] Therefore, the tubes provide a mechanism to meet a request for ashort TAT (Turn Around Time). Also, problem in the assembly line can beeasily identified by use the translucent material. Further, defectivetube pieces can be easily replaced if necessary.

[0030]FIG. 3 illustrates a cart 5C running on rails 5R laid at thebottom of the tube piece 5Ai. The cart 5C transfers the semiconductorwafer 6 between the apparatuses. The rails can be replaced with othertransfer mechanisms, such as gear driven mechanisms (not shown). The useof gears makes it is possible to build the assembly line at aninclination, or to transfer the semiconductor wafer vertically.

[0031] Next, as shown in FIG. 4, if the second apparatus 4 requires athird degree of cleanliness which is cleaner than above-mentioned thesecond degree of cleanliness of the first apparatus 3, a cleaning unit40 is arranged between the first apparatus 3 and the second apparatus 4within the transport enclosure 5.

[0032] The cleaning unit 40 is connected between the tube piece 5Ax and5Ay. One end of the tube piece 5Ax is connected the second stage 3-3 ofthe first apparatus 3, and the other end is connected to the cleaningunit 40 through a first shutter S1. One end of the tube piece 5Ay isconnected to the first stage 4-1 of the second apparatus 4, and theother end is connected to the cleaning unit 40 through a second shutterS2. The cleaning unit 40 includes a blowing unit 41 and an evacuatingunit 42. The blowing unit 41 is provided with a plurality of blow holeswhich blow a clean gaseous material on the semiconductor wafer 6 inorder to clean the wafer 6 and the cart 5C. The evacuating unit 42 isprovided with a plurality of evacuation holes which evacuate the gaseousmaterial. The gaseous material is used clean air. Generally, thecleaning unit 40 is called an air shower unit.

[0033] In this case, the inside of the first apparatus 3 and the tubepiece 5Ax is maintained the second degree of cleanliness, and the insideof the second apparatus 4 and tube piece 5 is maintained the thirddegree of cleanliness.

[0034] The semiconductor wafer 6 is transferred by the cart 5C from thesecond stage 3-3 to the cleaning unit 40 when the first shutter S1 isopened and the second shutter S2 is closed. Then the semiconductor wafer6 is cleaned when the first shutter S1 and the second shutter S2 areclosed by blowing the gaseous material and evacuating the air. Aftercleaning, the semiconductor wafer 6 on the cart 5C is transferred fromthe cleaning unit 40 to the tube piece 5Ay when the first shutter S1 isclosed and the second shutter S2 is opened.

[0035] The cleaning unit makes it possible to transfer the materialbetween apparatuses having different degree of cleanliness. Therefore,it is easy to design an assembly line which requires a variety ofcleanliness levels.

[0036] According to the present invention, the area within the cleanroom requires the highest degree of cleanliness is minimized. As such,manufacture costs are also minimized. Also, the present inventionfacilitates meeting a request for a short TAT as described above.

[0037] The present invention has been described with reference toillustrative embodiments, however, this description must not beconsidered to be confined only to the embodiments illustrated. Variousmodifications and changes of these illustrative embodiments and theother embodiments of the present invention will become apparent to oneskilled in the art from reference to the description of the presentinvention. It is therefore contemplated that the appended claims willcover any such modifications or embodiments as fall within the truescope of the invention.

What is claimed is:
 1. An assembly system located in a clean room, theclean room shielded from an external atmosphere and maintained at afirst degree of cleanliness, said assembly system comprising: a firstapparatus including a first chamber which receives a material and treatsa surface of the material with a first treatment; a second apparatusincluding a second chamber which receives the material and treats thesurface of the material with a second treatment, a transport enclosure,extending between the first apparatus and the second apparatus, whichtransports the material from the first apparatus to the secondapparatus, said transport enclosure being shielded from the clean roomand maintained a second degree of cleanliness which is cleaner than thefirst degree of cleanliness.
 2. The assembly system according to theclaim 1, further comprising a passing station which passes the materialto the first chamber; and wherein the first apparatus includes a firststage and a second stage, the first stage receiving the material fromthe passing station and introducing the material into the first chamber,the second stage receiving the material from the first chamber andpassing the material to the transport enclosure; wherein the secondapparatus includes a third stage and a fourth stage, the third stagereceiving the material from the transport enclosure and introducing thematerial into the second chamber, the fourth stage receiving thematerial from the second chamber and passing the material to outside. 3.The assembly system according to the claim 1, wherein the transportenclosure is composed of a substantially transparent tube.
 4. Theassembly system according to the claim 3, wherein the transportenclosure includes a cart having the loading the material loaded thereonand running on rails.
 5. The assembly system according to the claim 1, acontrol unit operable by a worker for controlling the first and secondapparatuses and the transport enclosure is located in the clean room. 6.The assembly system according to the claim 2, wherein the second chamberis maintained at a third degree of cleanliness which is cleaner than thesecond degree of cleanliness, wherein the transport enclosure includessequentially arranged first, second and third units, the first unitconnected to the second stage of the first apparatus and maintained thesecond degree of cleanliness, the third unit connected to the thirdstage of the second apparatus and maintained the third degree ofcleanliness, the second unit located between the first and third unitsand including a cleaning mechanism which cleans the material whenintroduced from the first unit.
 7. The assembly system according to theclaim 6, further comprising: a first shutter located between the firstunit and the second unit; a second shutter located between the secondunit and the third unit; wherein the material is transferred from thefirst unit to the second unit when the first shutter is opened and thesecond shutter is closed, wherein and the material is cleaned by thecleaning mechanism when the first and second shutters are closed, andwherein the material is transferred from the second unit to the thirdunit when the first shutter is closed and the second shutter is opened.8. The assembly system according to the claim 7, wherein the cleaningmechanism comprises a blow hole and an evacuation hole, wherein the blowhole blows a clean gaseous material on the material to clean thematerial, and wherein the evacuation hole evacuates the second unit. 9.The assembly system according to claim 5, wherein the material is asemiconductor wafer.
 10. The assembly system according to claim 1,wherein the second degree of cleanliness which is at least two timeshigher than the first degree of cleanliness.
 11. A method oftransferring a material from a first chamber to a second chamber in aclean room, the clean room shielded from an external atmosphere andmaintained a first degree of cleanliness, said method comprising:depositing the material in the first chamber; treating the material witha first treatment in the first chamber; transporting the material fromthe first chamber to a second chamber through an enclosure which isshielded from the clean room and maintained at a second degree ofcleanliness that is cleaner than the first degree of cleanliness;treating the material in the second chamber.
 12. The method according tothe claim 11, further comprising: controlling the first and secondchambers using a control unit located in the clean room.
 13. The methodaccording to the claim 11, wherein the material is a semiconductorwafer.
 14. The assembly system according to claim 11, wherein the seconddegree of cleanliness which is at least two times higher than the firstdegree of cleanliness.
 15. A transport enclosure for transferring amaterial from a first chamber to a second chamber, said transportenclosure comprising: a shielded conduit having a first end whichreceives the material from the first chamber and a second end whichdeposits the material in the second chamber; a transport mechanism whichtransports the material through the chamber from the first end to thesecond end; and a cleaning mechanism, located between said first andsecond ends, which cleans the material during transport of the materialby said transport mechanism.
 16. The transport enclosure according tothe claim 15, wherein the shielded conduit is composed of asubstantially transparent tube.
 17. The transport enclosure according tothe claim 15, further comprising: a first shutter located between thefirst chamber and the first end; a second shutter located between thesecond chamber and the second end; wherein the material is transferredfrom the first chamber to the shielded conduit when the first shutter isopened and the second shutter is closed, wherein the material is cleanedby the cleaning mechanism when the first and second shutters are closed,and wherein the material is transferred from the shielded conduit to thesecond chamber when the first shutter is closed and the second shutteris opened.
 18. The assembly system according to the claim 17, whereinthe cleaning mechanism comprises a blow hole and an evacuation hole,wherein the blow hole blows a clean gaseous material on the material toclean the material, and wherein the evacuation hole evacuates theshielded conduit.
 19. The assembly system according to claim 18, whereinthe material is a semiconductor wafer.